1. Field of the Invention
This invention relates in general to metered dose inhaler cloud chambers or spacers and, in particular, to a metered dose inhaler cloud chamber having an improved valve system and being capable of storing a pressurized medication dispenser within the spacer or cloud chamber when the medication dispenser is not in use.
More specifically, but without restriction to the particular embodiment and/or use which is shown and described herein for purposes of illustration, this invention relates to an improved cloud chamber for use with a metered dose inhaler, the cloud chamber having a one-way inspiratory air valve and one-way expiratory air valves utilizing the same elastomeric valve body, and which is capable of storing a pressurized medication dispenser, with which the cloud chamber is used, within the cloud chamber when the device is not in use.
2. Description of Related Art
As is known to those skilled in the art, cloud chambers have been used with pressurized medication dispensers for the treatment of persons having respiratory system problems responsive to inhalation therapy. Such devices, referred to as metered dose inhalers (MDI), are used for self-administered inhalation therapy wherein a metered dose of medication is dispensed from a pressurized medication dispenser in the form of a spray or mist which is directed for dispensing into a user's mouth for inhalation into the user's respiratory system.
The pressurized dispensing of such medication directly into a user's or patient's mouth has some objectionable drawbacks, including the uneven distribution of the sprayed medication which condenses on the tongue and inside the mouth rather than being applied to the respiratory system. The condensing of the medication on the tongue creates an objectionable taste, and can cause atrophy of the tongue over prolonged periods of use. Medication which condenses in such a manner on the tongue or inside the mouth is not utilized in the manner intended by the health care professional, and is in effect wasted.
In order to overcome such problems, it has been found that discharging the pressurized medication into a cloud chamber provides a much more effective and efficient means for distributing the medication into the respiratory system as intended. Breathing the mixture of medication and air drawn from the cloud chamber permits more of the medication to reach those portions of the user's respiratory system where the medication is intended to be applied, and is more effective in respiratory care treatment.
When using an MDI with a cloud chamber, it has been found to be preferable for the user to take repeated breaths through the cloud chamber to insure that all of the medication has been utilized in the manner intended. To this end it is preferable that the user not remove the cloud chamber from the mouth once inhalation therapy has begun. Accordingly, it is preferable that some provision be made for drawing inspiratory air in through the cloud chamber, and discharging expiratory air outside of the cloud chamber without removing the device from the user's mouth. Such a provision eliminates the necessity of a user coordinating the dispensing of the pressurized medication with inhalation of the inspiratory air. Also, in this manner the discharge of expiratory air outside of the cloud chamber, prevents the expiratory air, which contains higher levels of carbon dioxide and is normally laden with water vapor, from being re-breathed which would raise the carbon dioxide level and lower the oxygen levels of the user. In addition, if expiratory air is discharged into the cloud chamber, the medication will be blown back out of the device, and the high levels of water vapor from exhaled air will condense in the cloud chamber providing a re-breathing of detrimental bacteria.
The present invention incorporates a unique one-way inspiratory air and one-way expiratory air valving system which utilizes the same valve body to provide both functions through utilization of different parts of the same valve body for performing these functions.
The present invention also provides for the storage of the pressurized medication container within the cloud chamber so that the medication can be conveniently stored when the device in not in use. Without such a convenient storage provision, the medication container can become separated from the cloud chamber resulting in "lost" medicine, and the inability to self-administer the respiratory care treatment as scheduled. Furthermore, such a storage provision prevents debris from entering or clogging the pressurized medication dispenser outlet and eliminates the need for a separate cap to cover the open discharge end of the pressurized medication container.